I have a good friend who works as the caretaker of a vacation rental in Kauai (friends with jobs like that are always good to have!). I dropped by the vacation rental once to help her freshen up a few things for a guest. In the supply closet, I was amazed to find giant bottles of everying: dish soap, hand soap, shampoo and conditioner. Inside the rental, everything is set up like an average home, complete with normal-sized bottles of soap, shampoo, etc. Between guests, instead of replacing the entire bottle or leaving the next visitor to find a half-empty bottle, my friend refills the normal-sized bottles with the jumbo refill bottles. Pretty clever.
This can also be done at home. Instead of buying new hand soap bottles every time we run out, we get refill bottles at Costco and refill all the little bottles in the house about once a month. It’s easy to do the same thing with dish soap and even food items like pepper shakers and Tabasco sauce.